Seeing What You Mean

Readers of 13.7 may have noticed headlines this past week trumpeting the latest "brain reading" breakthroughs coming out of UC Berkeley's neuroscience laboratories. I've written about related work before, here, here, and here. This latest research is dazzling. Direct measurement of neural activity in higher areas of auditory cortex allows scientists to determine what continuous speech sounds (words, sentences) a person is currently hearing. It's hard to overstate the daunting character of this achievement.

The relation of speech to its physical substrate is mysterious at best. One and the same acoustic event can be experienced as different speech sounds, and different acoustic events can be experienced as the same speech sound. The perception of speech, such a commonplace event in our lives, is surely one of our most impressive and, from a scientific perspective, baffling cognitive achievments.

If we can "read off" experienced words by direct measurement of the brain, then it may be just a matter of time before we can determine by similar measurements what speech forms are being entertained in voluntary thought. The ability to do this might be the basis of new prostheses to help those who are otherwise incapacitated, stroke patients for example, communicate with those around them.

Many people find the prospect of this vaguely threatening; the BBC reporter whose interview with UC Berkeley neuroscientist Robert Knight can be downloaded here, felt the need to ask whether this sort of technology could be used nefariously to penetrate into the thoughts of others. Knight, who has been a colleague of mine at UC Berkeley, gave an amusing but unsatisfactory reply: "I think how Doctor Strangeglove might use this [technology] in the future might be slightly above my pay grade!"

Actually, these worries are entirely misguided.

A person's mind is an open book and we are excellent readers. I can tell what you are thinking and feeling just by watching you, by paying attention to what you do, by observing your facial expression and your posture (not to mention, by listening to your words!). Our ability to understand each other, our powers of empathy, sympathy, mutual anticipation and joint attention are the very basis of lives together as human beings.

I think we fear that what makes brain-reading special is that it is a way of knowing what people are thinking and feeling that by-passes the need for observing them, as if it afforded a kind of direct access to the mind itself, a look into the normally hidden backstage of human being. But this is a wrongheaded conception of the mind. You are not your brain. Mind is not inside us; it is rather, the dynamic activity of the whole, embodied, environmentally situated human being.

One last very important point: the target of this research is not neural correlates of thought. The target is the neural correlates of acts of communication (the perception and production of speech). But communication is not something that happens in the private sphere of our own interior worlds. It is something we undertake, together, in contexts of shared interests and concerns. It is more like soccer, with all of us running around together chasing the same ball, than it is like dreaming.

If this eventual research aim is achieved, we will not have succeeded in unlocking a person's thoughts and feelings; we will have succeeded in enabling a person to communicate with others.

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